Investigation of the central organization of the autonomic nervous system. Anatomical methods are used to study the typographic representation of individual visceral organs within the dorsalmotor nucleus of the vagus and nucleus solitaries using Horseradish Peroxidase and Autoradiographic methods. The distribution of various neuropeptides, transmitters and receptors within each subnucleus are being mapped with immunohistochemical, (IHC), and autoradiographic methods. Discrete central inputs to each subnucleus from brainstem and rostral neuroaxial levels are being studied to clarify mechanisms of central control of individual visceral organs. The work is being accomplished in pigeons and rabbits.